Index: linux-2.6.10-ckdev/arch/mips/kernel/irixelf.c
===================================================================
--- linux-2.6.10-ckdev.orig/arch/mips/kernel/irixelf.c	2004-12-25 10:14:47.000000000 +1100
+++ linux-2.6.10-ckdev/arch/mips/kernel/irixelf.c	2005-01-10 14:36:17.823328848 +1100
@@ -127,7 +127,7 @@
 	end = PAGE_ALIGN(end);
 	if (end <= start)
 		return;
-	do_brk(start, end - start);
+	do_brk_locked(start, end - start);
 }
 
 
Index: linux-2.6.10-ckdev/arch/x86_64/ia32/ia32_aout.c
===================================================================
--- linux-2.6.10-ckdev.orig/arch/x86_64/ia32/ia32_aout.c	2004-12-25 10:14:47.000000000 +1100
+++ linux-2.6.10-ckdev/arch/x86_64/ia32/ia32_aout.c	2005-01-10 14:36:17.824328696 +1100
@@ -114,7 +114,7 @@
 	end = PAGE_ALIGN(end);
 	if (end <= start)
 		return;
-	do_brk(start, end - start);
+	do_brk_locked(start, end - start);
 }
 
 #if CORE_DUMP
@@ -324,7 +324,7 @@
 		pos = 32;
 		map_size = ex.a_text+ex.a_data;
 
-		error = do_brk(text_addr & PAGE_MASK, map_size);
+		error = do_brk_locked(text_addr & PAGE_MASK, map_size);
 		if (error != (text_addr & PAGE_MASK)) {
 			send_sig(SIGKILL, current, 0);
 			return error;
@@ -360,7 +360,7 @@
 
 		if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
 			loff_t pos = fd_offset;
-			do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
+			do_brk_locked(N_TXTADDR(ex), ex.a_text+ex.a_data);
 			bprm->file->f_op->read(bprm->file,(char *)N_TXTADDR(ex),
 					ex.a_text+ex.a_data, &pos);
 			flush_icache_range((unsigned long) N_TXTADDR(ex),
@@ -469,7 +469,7 @@
 		}
 #endif
 
-		do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
+		do_brk_locked(start_addr, ex.a_text + ex.a_data + ex.a_bss);
 		
 		file->f_op->read(file, (char *)start_addr,
 			ex.a_text + ex.a_data, &pos);
@@ -493,7 +493,7 @@
 	len = PAGE_ALIGN(ex.a_text + ex.a_data);
 	bss = ex.a_text + ex.a_data + ex.a_bss;
 	if (bss > len) {
-		error = do_brk(start_addr + len, bss - len);
+		error = do_brk_locked(start_addr + len, bss - len);
 		retval = error;
 		if (error != start_addr + len)
 			goto out;
Index: linux-2.6.10-ckdev/fs/binfmt_aout.c
===================================================================
--- linux-2.6.10-ckdev.orig/fs/binfmt_aout.c	2004-12-25 10:14:50.000000000 +1100
+++ linux-2.6.10-ckdev/fs/binfmt_aout.c	2005-01-10 14:36:17.824328696 +1100
@@ -50,7 +50,7 @@
 	start = PAGE_ALIGN(start);
 	end = PAGE_ALIGN(end);
 	if (end > start) {
-		unsigned long addr = do_brk(start, end - start);
+		unsigned long addr = do_brk_locked(start, end - start);
 		if (BAD_ADDR(addr))
 			return addr;
 	}
@@ -323,10 +323,10 @@
 		loff_t pos = fd_offset;
 		/* Fuck me plenty... */
 		/* <AOL></AOL> */
-		error = do_brk(N_TXTADDR(ex), ex.a_text);
+		error = do_brk_locked(N_TXTADDR(ex), ex.a_text);
 		bprm->file->f_op->read(bprm->file, (char *) N_TXTADDR(ex),
 			  ex.a_text, &pos);
-		error = do_brk(N_DATADDR(ex), ex.a_data);
+		error = do_brk_locked(N_DATADDR(ex), ex.a_data);
 		bprm->file->f_op->read(bprm->file, (char *) N_DATADDR(ex),
 			  ex.a_data, &pos);
 		goto beyond_if;
@@ -347,7 +347,7 @@
 		map_size = ex.a_text+ex.a_data;
 #endif
 
-		error = do_brk(text_addr & PAGE_MASK, map_size);
+		error = do_brk_locked(text_addr & PAGE_MASK, map_size);
 		if (error != (text_addr & PAGE_MASK)) {
 			send_sig(SIGKILL, current, 0);
 			return error;
@@ -382,7 +382,7 @@
 
 		if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
 			loff_t pos = fd_offset;
-			do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
+			do_brk_locked(N_TXTADDR(ex), ex.a_text+ex.a_data);
 			bprm->file->f_op->read(bprm->file,
 					(char __user *)N_TXTADDR(ex),
 					ex.a_text+ex.a_data, &pos);
@@ -488,7 +488,7 @@
 			error_time = jiffies;
 		}
 
-		do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
+		do_brk_locked(start_addr, ex.a_text + ex.a_data + ex.a_bss);
 		
 		file->f_op->read(file, (char __user *)start_addr,
 			ex.a_text + ex.a_data, &pos);
@@ -512,7 +512,7 @@
 	len = PAGE_ALIGN(ex.a_text + ex.a_data);
 	bss = ex.a_text + ex.a_data + ex.a_bss;
 	if (bss > len) {
-		error = do_brk(start_addr + len, bss - len);
+		error = do_brk_locked(start_addr + len, bss - len);
 		retval = error;
 		if (error != start_addr + len)
 			goto out;
Index: linux-2.6.10-ckdev/fs/binfmt_elf.c
===================================================================
--- linux-2.6.10-ckdev.orig/fs/binfmt_elf.c	2004-12-25 10:14:50.000000000 +1100
+++ linux-2.6.10-ckdev/fs/binfmt_elf.c	2005-01-10 14:36:17.825328544 +1100
@@ -88,7 +88,7 @@
 	start = ELF_PAGEALIGN(start);
 	end = ELF_PAGEALIGN(end);
 	if (end > start) {
-		unsigned long addr = do_brk(start, end - start);
+		unsigned long addr = do_brk_locked(start, end - start);
 		if (BAD_ADDR(addr))
 			return addr;
 	}
@@ -408,7 +408,7 @@
 
 	/* Map the last of the bss segment */
 	if (last_bss > elf_bss) {
-		error = do_brk(elf_bss, last_bss - elf_bss);
+		error = do_brk_locked(elf_bss, last_bss - elf_bss);
 		if (BAD_ADDR(error))
 			goto out_close;
 	}
@@ -448,7 +448,7 @@
 		goto out;
 	}
 
-	do_brk(0, text_data);
+	do_brk_locked(0, text_data);
 	if (!interpreter->f_op || !interpreter->f_op->read)
 		goto out;
 	if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
@@ -456,7 +456,7 @@
 	flush_icache_range((unsigned long)addr,
 	                   (unsigned long)addr + text_data);
 
-	do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
+	do_brk_locked(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
 		interp_ex->a_bss);
 	elf_entry = interp_ex->a_entry;
 
@@ -1025,7 +1025,7 @@
 	len = ELF_PAGESTART(elf_phdata->p_filesz + elf_phdata->p_vaddr + ELF_MIN_ALIGN - 1);
 	bss = elf_phdata->p_memsz + elf_phdata->p_vaddr;
 	if (bss > len)
-		do_brk(len, bss - len);
+		do_brk_locked(len, bss - len);
 	error = 0;
 
 out_free_ph:
Index: linux-2.6.10-ckdev/include/linux/mm.h
===================================================================
--- linux-2.6.10-ckdev.orig/include/linux/mm.h	2005-01-10 14:34:36.844679936 +1100
+++ linux-2.6.10-ckdev/include/linux/mm.h	2005-01-10 14:36:17.826328392 +1100
@@ -710,6 +710,7 @@
 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
 
 extern unsigned long do_brk(unsigned long, unsigned long);
+extern unsigned long do_brk_locked(unsigned long, unsigned long);
 
 /* filemap.c */
 extern unsigned long page_unuse(struct page *);
Index: linux-2.6.10-ckdev/mm/mmap.c
===================================================================
--- linux-2.6.10-ckdev.orig/mm/mmap.c	2005-01-10 14:30:30.056197488 +1100
+++ linux-2.6.10-ckdev/mm/mmap.c	2005-01-10 14:36:17.827328240 +1100
@@ -1827,6 +1827,20 @@
 
 EXPORT_SYMBOL(do_brk);
 
+/* locking version of do_brk. */
+unsigned long do_brk_locked(unsigned long addr, unsigned long len)
+{
+	unsigned long ret;
+
+	down_write(&current->mm->mmap_sem);
+	ret = do_brk(addr, len);
+	up_write(&current->mm->mmap_sem);
+
+	return ret;
+}
+
+EXPORT_SYMBOL(do_brk_locked);
+
 /* Release all mmaps. */
 void exit_mmap(struct mm_struct *mm)
 {
Index: linux-2.6.10-ckdev/mm/nommu.c
===================================================================
--- linux-2.6.10-ckdev.orig/mm/nommu.c	2004-12-25 10:14:51.000000000 +1100
+++ linux-2.6.10-ckdev/mm/nommu.c	2005-01-10 14:36:17.827328240 +1100
@@ -237,6 +237,11 @@
 	return mm->brk = brk;
 }
 
+unsigned long do_brk_locked(unsigned long addr, unsigned long len)
+{
+	return -ENOMEM;
+}
+
 /*
  * Combine the mmap "prot" and "flags" argument into one "vm_flags" used
  * internally. Essentially, translate the "PROT_xxx" and "MAP_xxx" bits